Don't hang the task if something other than the renderer fails (e.g. model loading)

ui/sd_internal/task_manager.py

@@ -372,6 +372,8 @@ def thread_render(device):
             session_cache.keep(task.request.session_id, TASK_TTL)
         except Exception as e:
             task.error = e
+            task.response = {"status": 'failed', "detail": str(task.error)}
+            task.buffer_queue.put(json.dumps(task.response))
             print(traceback.format_exc())
             continue
         finally: